path: root/lib/HttpServ.cc

#include "Socket.h"
#include "Action.h"
#include "HttpServ.h"
#include "Buffer.h"
#include "ReadJob.h"
#include "CopyJob.h"
#include "Task.h"
#include "config.h"

String endhl = "\r\n", endnl = "\n";

class ProcessRequest : public Task {
  public:
      ProcessRequest(Action *, const Socket &, const String &, int);
      virtual ~ProcessRequest() {}
    virtual String GetName();
  protected:
    virtual int Do();
  private:
    String GetMime(const String &);
    bool ParseUri(String &, String &, Handle *);
    void ParseVars(Handle *, int);
    void ShowError(Handle *);
    void SendHeads(Handle *, const String &, const String & = "", time_t = -1);
    void SendRedirect(Handle *);

    String file, domain, t;
    Buffer b;
    Task * c, * a;
    Action * f;
    int len, localport;
    Action * p;
    Socket s;

    String name, host;
    Variables * Vars;
    bool bad, hasvars, post;
};

ProcessRequest::ProcessRequest(Action * ap, const Socket & as, const String & aname, int aport) : localport(aport), p(ap), s(as), name(aname) {
    SetBurst();
}

String ProcessRequest::GetName() {
    return "Processing HTTP request";
}

int ProcessRequest::Do() {
    switch (current) {
    case 0:
        if (!s.IsConnected()) return TASK_DONE;

        c = new ReadJob(&s, &b);
        WaitFor(c);
	current = 1;
        Suspend(TASK_ON_HOLD);

    case 1:
        delete c;

        bad = false;

        cerr << "---- Got a request from handle " << s.GetHandle() << " \n";
    
        post = ParseUri(file, domain, &b);

        len = -1;
        do {
    	    b >> t;
	    // cerr << "Read Request (n): " << t << endl;
	    if ((t.strstr("Content-Length: ") == 0) || (t.strstr("Content-length: ") == 0)) {
		// cerr << "Saw 'Content-Lenght:', reading length from '" << t.extract(16) << "'\n";
	        len = t.extract(16).to_int();
	    }
	    if (t.strstr("Host: ") == 0) {
		host = t.extract(6);
	    }
	} while (t.strlen());
	
	// cerr << "---- Processing it.\n";

        hasvars = false;

	if (post) {
	    // On a pas eu de ligne 'Content-Length' mais on a eu une méthode POST.
	    // Cela est une erreur.
	    if (len == -1) {
		cerr << "Error: method POST but no Content-Length\n";
		bad = true;
		Vars = new Variables();
	    } else {
		// cerr << "Got a POST request. Parsing variables. (len = " << len << ")\n";
	        // Les variables seront initialisées ici.
		hasvars = true;
	    }
	} else {
	    Vars = new Variables();
	}

	current = 2;
	if (hasvars && (len)) {
	    c = new CopyJob(&s, &b, len);
	    WaitFor(c);
	    Suspend();
	} else {
	    c = 0;
	}

    case 2:
	if (hasvars) {
	    if (c) delete c;
	    ParseVars(&b, len);
	}
    
	cerr << " Domain = '" << domain << "' - File = '" << file << "'\n";
	
        if (!bad) {
	    // Nous vérifions le domaine.
	    if (domain != "") {
		bad = true;
	        // Les domaines valides sont '/', '/bin' et '/image'.
		if (domain == "/image") bad = false;
		if (domain == "/bin") bad = false;
		if (domain == "/") bad = false;
		if (bad) {
		    cerr << "Error: bad domain.\n";
		}
	    } else {
		// L'url sans domaine ni fichier est valide. (cela arrive sur certains navigateurs...)
		bad = (file != "");
	    }
	}

        a = 0;

	if (bad) {
	    ShowError(&b);
	} else {
	    if (((domain == "") || (domain == "/")) && (file == "")) {
		// Si le navigateur a demandé l'URL '/', alors on renvoie une notification
		// de redirection.
		SendRedirect(&b);
	    } else if (domain == "/bin") {
		// Le domaine 'bin' est réservé aux actions. On cherche donc l'action à effectuer.
	        if ((f = p->Look4URL(file))) {
    		    SendHeads(&b, "text/html");
		    a = f->Do(Vars, &s);
		} else {
		    ShowError(&b);
	        }
	    } else {
		// Dans tous les autres cas de domaine, on cherche le fichier dans le répertoire datas.
	        // On utilise try au cas où le fichier n'existe pas et donc que le constructeur
	        // d'input renvoie une erreur.
	        try {
	    	    Handle * i = new Input(String("datas/") + file);
	    	    SendHeads(&b, GetMime(file), String("Accept-Ranges: bytes") + endhl + "Content-Length: " + (unsigned long long int) i->GetSize() + endhl, i->GetModif());
		    i->SetNonBlock();
		    a = new CopyJob(i, &s);
		    cerr << "File found, dumping.\n";
		}
	        catch (IOGeneral e) {
		    ShowError(&b);
		    cerr << "File not found, error showed.\n";
		}
	    }
	}
    
	if (a) a->Stop();
    
	delete Vars;
	// cerr << "---- Sending header buffer.\n";
	c = new CopyJob(&b, &s, -1, false);
	WaitFor(c);
	current = 3;
	Suspend();

    case 3:
	delete c;
    
	if (a) {
	    // cerr << "---- Sending contents.\n";
	    a->Restart();
	    WaitFor(a);
	    current = 4;
	    Suspend();
	}

    case 4:
	if (a) delete a;
    
        cerr << "---- End of Request.\n";
    }
    return TASK_DONE;
}

void ProcessRequest::ParseVars(Handle * s, int len) {
    String t, v;
    char conv[3], l;
    int hconv, nbvars;
    ssize_t pos = 0, next;
    
    t = "";
    for (int i = 0; i < len; i++) {
	s->read(&l, 1);
	t += l;
    }
    cerr << "Post variables line: '" << t << "'\n";
    
    
    // Les variables sont sous la forme 'var1=val1&var2=val2&val3=var3'. Donc le nombre d'occurences
    // du caractère '=' indique le nombre de variables.
    nbvars = t.strchrcnt('=');
    Vars = new Variables(nbvars);
    
    for (int i = 0; i < nbvars; i++) {
	// Les variables sont sous la forme 'var1=val1&var2=val2&val3=var3'. Donc on cherche le caractère
	// & dans la chaine POST.
	next = t.strchr('&', pos);
	if (next < 0) next = t.strlen();
	v = "";
	while (pos != next) {
	    switch (t[pos]) {
	    // Le navigateur encode les caractères spéciaux à l'aide du format %XX où XX indique
	    // la valeur hexadécimale du caractère. Nous encodons surtout les caractères
	    // ' ', '=', '%', et '/' avec cette technique.
	    case '%':
		pos++;
		conv[0] = t[pos++];
		conv[1] = t[pos++];
		conv[2] = '\0';
		sscanf(conv, "%x", &hconv);
		v += ((char) hconv);
		break;
	    // Certains navigateurs utilisent '+' pour indiquer ' ' (qui est illégal) au lieu
	    // d'utiliser %20.
	    case '+':
		v += ' ';
		pos++;
		break;
	    default:
    		v += t[pos++];
	    }
	    Vars->SetTo(i, v);
	}
	pos++;
    }
}

/*
 * Cette fonction renverra true si la méthode est une méthode POST.
 * Les Strings domain et file seront modifiées afin de renvoyer le domaine
 * et le fichier lut. La string s doit donner la première ligne de la requète,
 * c'est à dire la méthode demandée par le client.
 */

bool ProcessRequest::ParseUri(String & file, String & domain, Handle * s) {
    String t, Uri;
    bool post = false;
    const char * p = 0;
    ssize_t sppos;

    *s >> t;
    cerr << "Read Request (1): " << t << endl;
    
    bad = false;
    
    // p nous indiquera la position de la chaîne URL.
    switch (t[0]) {
    case 'P': /* POST? */
	if (t.extract(1, 4) == "OST ") {
    	    p = t.to_charp(5);
	    post = true;
	} else {
	    cerr << "Error: unknow request.\n";
	    bad = true;
	}
	break;
    case 'G': /* GET? */
	if (t.extract(1, 3) == "ET ") {
	    p = t.to_charp(4);
	} else {
	    cerr << "Error: unknow request.\n";
	    bad = true;
	}
	break;
    default:
	cerr << "Error: unknow request.\n";
	bad = true;
    }
    
    if (!bad) {
	ssize_t poshttp, posslash;
        Uri = p;
	sppos = Uri.strrchr(' ');
	p = Uri.to_charp(0, sppos - 1);
	Uri = p;
	// On enlève tout le host spécifié éventuellement dans la requete.
	if ((poshttp = Uri.strstr("http://")) > 0) {
	    Uri = Uri.to_charp(poshttp + 7);
	    posslash = Uri.strchr('/');
	    // Certains navigateurs indiqueront uniquement http://host comme URL.
	    if (posslash >= 0) {
		host = Uri.extract(0, posslash - 1);
		Uri = Uri.to_charp(posslash);
	    } else {
		host = Uri;
		Uri = "";
	    }
	}
	posslash = Uri.strrchr('/');
	file = Uri.to_charp(posslash + 1);
	if (posslash > 0) {
	    domain = Uri.to_charp(0, posslash - 1);
	} else {
	    domain = "";
	}
    }
    return post;
}

/*
 * Ceci sert à rediriger le navigateur vers l'url de démarrage.
 */
void ProcessRequest::SendRedirect(Handle * s) {
    *s << "HTTP/1.1 301 Moved Permanently" << endhl << 
	 "Server: " << name << endhl <<
	 "Location: http://" << host << "/bin/start" << endhl <<
	 "Cache-Control: no-cache" << endhl <<
	 "Connection: closed" << endhl <<
	 "Content-Type: text/html" << endhl << endhl <<
	 "<HTML><HEAD><TITLE>301 - Moved Permanently</TITLE></HEAD>" << endnl <<
	 "<BODY><center><b><h2>You should be redirected to the " << endnl << endnl <<
	 "<a href=\"http://" << host << "/bin/start\">start page</a></h2></b></center>" << endnl <<
	 "</BODY></HTML>" << endnl;
}

/*
 * Nous envoyons les entetes de réponse HTTP.
 */

void ProcessRequest::SendHeads(Handle * s, const String & mime, const String & extra, time_t lm) {
    time_t t = time(NULL);
    struct tm * ft = gmtime(&t);
    char buf[1024];
    strftime(buf, 1024, "%a, %d %b %Y %H:%M:%S GMT", ft);
    *s << "HTTP/1.1 200 OK" << endhl <<
	  "Date: " << buf << endhl <<
	  "Server: " << name << endhl;
    if (lm >=0) {
	ft = gmtime(&lm);
	strftime(buf, 1024, "%a, %d %b %Y %H:%M:%S GMT", ft);
    }
    *s << "Last-Modified: " << buf << endhl << extra <<
	  "Connection: closed" << endhl << 
	  "Content-Type: " << mime << endhl << endhl;
}

/*
 * Affichage d'une erreur 404.
 */

void ProcessRequest::ShowError(Handle * s) {
    *s << "HTTP/1.1 404 Not Found" << endhl <<
         "Server: " << name << endhl <<
	 "Cache-Control: no-cache" << endhl <<
         "Connection: closed" << endhl <<
         "Content-Type: text/html" << endhl << endhl <<
	 "<HTML><HEAD><TITLE>404 - Error</TITLE></HEAD>" << endnl <<
	 "<BODY><center><b><h2>The server was unable to process your query</h2></b></center>" << endnl <<
	 "Click <A HREF=\"/\">here</A> to go the main page." <<
	 "</BODY></HTML>" << endnl;
}

/*
 * Sert à déterminer le type mime à partir de l'extension du fichier.
 * Par défaut, nous mettons "text/plain".
 */

String ProcessRequest::GetMime(const String & f) {
    String ext;
    size_t ppos;
    
    ppos = f.strrchr('.');
    
    if (ppos >= 0) {
	ext = f.extract(ppos + 1);
	if (ext == "jpg") return "image/jpeg";
	if (ext == "jpeg") return "image/jpeg";
	if (ext == "htm") return "text/html";
	if (ext == "html") return "text/html";
	if (ext == "gif") return "image/gif";
	if (ext == "png") return "image/png";
	if (ext == "class") return "application/octet-stream";
    }
    
    return "text/plain";
}

HttpServ::HttpServ(Action * ap, int port, const String & nname) throw (GeneralException) : p(ap), name(nname), localport(port) {
    bool r = true;
    
    cerr << "Initialising Mini HTTP-Server on port " << localport << endl;
    
    r = Listener.SetLocal("", port);
    if (!r) {
	throw GeneralException("Initialisation of the Mini HTTP-Server failed: can't bind");
    }
    
    r = Listener.Listen();
    
    if (!r) {
	throw GeneralException("Initialisation of the Mini HTTP-Server failed: can't listen");
    }
    
    Listener.SetNonBlock();
    WaitFor(&Listener, W4_STICKY | W4_READING);
    
    cerr << "Mini HTTP-Server '" << name << "' ready and listening for port " << port << endl;
}

HttpServ::~HttpServ(void) {
    Listener.close();
}

int HttpServ::Do() {
    try {
	Socket s = Listener.Accept();
	s.SetNonBlock();
	new ProcessRequest(p, s, name, localport);
    }
    catch (GeneralException) {
    }
    return TASK_ON_HOLD;
}

String HttpServ::GetName() {
    return String("Mini HTTP-Server '") + name + "'";
}